It is known to use pneumatic actuators to operate braking systems on electric drawworks, such as those disclosed in U.S. Pat. Nos. 7,527,245 and 8,079,569. Referring to FIG. 1, an example of such drawworks is shown and labelled as A, with the pneumatic actuators labelled as B. Such actuators are pneumatically powered to compress biasing springs contained therein, and to retract an actuating rod that removes force applied to brake bands C disposed around brake drums E on drawworks A, thereby allowing cable drum D on drawworks A to rotate. Upon removal of the pressurized air to actuators B, the biasing springs extend the actuating rod to apply force or tension to brake bands C, thereby stopping rotation of cable drum D. Pneumatically-operated actuators have shortcomings, one of which includes their susceptibility to corrosion and, therefore, failure to operate correctly once corroded. Another shortcoming is that air is compressible, which can make the control of pneumatically-operated actuators in a braking mechanism for a drawworks difficult.
It is, therefore, desirable to provide a hydraulically-operated actuator for a braking mechanism for a drawworks that overcomes the shortcomings of pneumatically-operated actuators.